EXPLORATION AND SAMPLING
Key features of the Dando Terrier MK2 include the auto trip hammer and multiple rod pulling
don’ t facilitate good sample recovery using rotary methods this is the most refined, versatile and functional rig of its kind,” Dando reports.“ In the mineral sector, the rig has been adopted by customers sampling alluvial gold, for example, where the loose geology can prevent adequate core retrieval from rotary coring methods. The Terrier duplex system advances both casing and sampler simultaneously preventing hole collapse, and the sample is quickly retrieved from the sample barrel within a plastic liner which can be
immediately capped to ensure perfect sample preservation until analysis is required at the lab.”
Recent improvements in processing technology has led many miners to choose to reprocess their existing tailing beds in order to extract remaining minerals. Sampling the beds often requires rigs able to retrieve samples to shallow depths up to 15 m and the Terrier MK2 is ideal for this kind of work. As the percussive system does not need drilling fluids, there is reduced risk of contamination and no need for space and time required to prepare water supply and mud pits.
The mast on the new rig has a number of developments. A 300 mm hydraulic dump allows the mast to be raised and lowered and as a result the rig can be tracked to a new drill location with the mast erect. When drilling multiple holes in close proximity, the foot of the mast can be raised and the rig tracked directly over a completed borehole to the next location to start drilling immediately. The speed with which redeployment can be carried out saves valuable time.
Also aimed at reducing redeployment time, a swing-out pullback ring provides open access to the borehole and, along with a stainless steel rod guide, means that multiple rods can be safely pulled out prior to removal. The end result is more holes per shift.
The percussion hammer itself is capable of up to 50 blows per minute along its full drop height. This provides for impressive penetration rates when sampling.
In addition, the trip-hammer has an autostop feature built in so that operation ceases when it reaches the foot of the mast. This allows the driller to step away from the levers and do other work during sampling, safe in the knowledge that when the sample tube is full, or if a void in the geology is encountered causing the hammer to drop to the foot of the mast, the automatic cutoff will prevent damage to the rig.
The console has been redesigned to allow for clear sighting of the borehole while drilling and the ergonomic controls ensure the rig is simple to use. The anvil also has a new design. The new system has a quick release fitting that self-locates on the drive rods without the need for threaded connectors.“ Like many of the features of the new rig, the details reflect Dando’ s attention to what customers really need: less fuss, less time wasted, quicker completion of projects, better safety.”
As per the original Terrier rig, the deck can
We are better together
MWH is now part of Stantec. Together we offer expanded mining, tailings, water, and environmental services to the mining community.
Visit stantec. com / mining / MWH to learn more.